Alternating-current electric meter.



No. 693,537. Patented Feb. la, |902.

E. ATAuLT.

ALTERNATING CURRENT ELECTRIC METER. (Application led Max'. 15, 1901.)(No Model.)

Z Inventor UNiinn STATES PATENT FFIC.

EMILE BATAULT, OF GENEVA, SVITZERLAND.

ALTERNATlNG-CURRENT ELECTRIC METER.

SPECIFICATION forming part of Letters Patent No. 693, 537, datedFebruary 18, 1902.

Application led March v15, 1901. Serial No. 51.229. (No model.)

To all whom it may concern:

Beit known that I, EMILE BATAULT, a citizen of the SwissRepnblic,residingat Geneva,

in the canton of Geneva, Republic of Swit? rent in the work-circuit andthe other field being due to and varying with the electrical pressure.In my Patent No. 652,453, dated June 26, 1900, I show a meter of thistype using a disk armature rotating in a plane closely adjacent4 to twomagnetic poles each carrying a shunt-coil, and one or both of said polesbeing provided with one or two series coils for inducing in the armaturemagnetic fields didering in phase and eccentric to the fields induced bythe shunt-coils, to thereby cault currents thus induced in the armatureproduce a checking or braking eect, which in the measurement of currentsof substantantially constant electromotive force can alone be reliedupon to oppose the rotative tendency and to edect a proper registra'tion. When, however, the electromotive force is subject to variation, Imake use of a separate permanent magnet, as described in said patent, tosecure a constant checking or braking eect which shall 'be independentof any variations in the voltage. When such a permanent magnet is usedfor the purpose mentioned, it will be evident that the checking orbraking eect imposed upon the armature will be due to twofactors-namely, the magnetic retardation imposed by the permanent magnetand the generation of Foucault currents by induction-and since, asstated, the latter factor is a variable one, changing with changes involtage, a correspendin g error in the registration will result,

and the meter will register disproportionately greater or fewer watts asthe voltage falls or rises. In order that this error may be practicallyminimized, I find it necessary, in the construction of a meter for thepurpose indicated, to depend upon the permanent magnet for the greater.bulk of the braking effect. If, for example, fifty per cent. of thebraking or checking edect is due to the permanent magnet and fifty percent. to the inductive effeet of the coils, a variation of fiftypercent. in the latter elfect would result in an error of twenty-fivepercent. in the total checking or braking action; but if ninety percent. of the braking or checking eect is due to the permanent magnet andten per cent. to the effect of induction a similar variation in thelatter effectwll result only in a variation of five per cent. in theentire braking or checking action. In order to secure this result, Iemploy between the two branches of the shunt-magnet a magnetic bridge ordiverter made, for example, of laminated iron, and by means of whichwill be secured a partial closing of the magnetic lines of force belowthe armature, so as to diminish in consequence the number of magneticlines of force which aect the armature. This magnetic bridge or diverteris placed between the shunt-coils ses andthe revolving armature andpreferably by the latter coils will not be weakened, but' will be ratherstrengthened. It is also possible to so arrange the magnetic diverterthat it will perform the additional function of the closed short-circuitwindings referred to in my said patent and by means of which I overcomean error noted when used on highly-inductive circuits.

My objects, generally, are to carry out these ideas in a simple andeconomical manner, as well as to improve and simplify the details ofconstruction, all as will be hereinafter described and claimed.

In order that the improvements may be better understood, attention isdirected to the accompanying drawings, forminga part of thisspecification, and in whichy Figure 1 is a front elevation, partly insection; Fig. 2, a section on the line 2 2 of Fie'.

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1; Fig. 3,-a section on the line 3 3 of Fig. l; Fig. 4, a sectiony onthe line 4 4 ofl Fig. 3; Fig. 5, a longitudinal section illustrating amodification; Fig. 6, a section on the line 6 6 of Fig. 5, and Fig. 7asection showing a modified form of operating-magnet.

In .all of the above views corresponding parts are represented by thesame numerals of reference.

Referring first to Figs.. 1, 2, 3, and 4,'the main operating-magnet isshown as being formed of a yoke 1, the two legs ofwhich are formed oflaminated metal 2 2 and 3 3, se-

cured on opposite sides of the yoke and each l pair of legs receiving ashunt-coil 4 4, both of said coils being preferably in series with eachother and being connected across the line. One or both of the sectionsof each of the legs of thev magnet may be provided with a series coil5,.as shown, which coil or coils' may be arranged in any suitable way,as suggested in saidl patent,.and which are. in series with thework-circuit, so .as to be induenced by the current to be measured.Mounted above the poles of the magnet is a disk armature 6, carried on aVertical shaft 7, which shaft is connected with a register. (Not shown.)Mounted, preferably, between the shunt-coils 4'and the series coils 5 isa magnetic bridge or diverter.- 8, formed, preferably, of iron plateshaving openings through which the poles extend, as shown. These openingsmay be larger than is necessary to receive the pole-pieces, so that freespaces will be formedbetween the poles and the adjacent surface off-'thebridge or diverter. This distance between the cores of the magnet andthe bridge may vary, which factor determines the amountof lines offorcev which may be diverted through the bridge and from thearmature,.it being obvious that when the bridge or diverteris close tothe cores less lines of -force will be permitted to pass through thearmature to act upon it than is otherwise the case. This free space isdetermined by experiment in order that the meter may give properindications, not only under changes in the voltage, but also underchanges in the periodicity of the alternating-current induencing thecoils. With this construction'each nof the iron plates comprising thebridge or di. verter completely surrounds each core vand constitutes, inpractice, a closedA short-circuit winding around the core, correspondingclosely in construction and operation with the short-circuit windingsreferred to in my said patent. The number o plates employed in theconstruction of the bridge or diverter yvaries according to theirthickness and to the complete section that is desired to secure theproper results. Normally this complete section may be smaller than thesection of one core, as a certain number of thc lines of force producedin the shunt-cores are not derived through the bridge, but pass throughthe rotating armature 6 to the stationary armature tions of the diverteror bridge, as explained, g

separate short-circuit windings may-belemployed, as described in saidpatent, when necessary, in which latter case the magnetic bridge ordiverter may extend in the space between the two-cores, as will beunderstood,

so as to perform the single function of diverting a part of the lines offorce therefrom.

In meters for alternating currents having a permanent magnet foreifecting a constantl braking or checking action on the disk-armatureitfrequently happens that a short circuit in the meter tends -to 'weakenthe magnet, andthereby change its normal standard. To avoid thisdifficulty', I described in my patent a movable armature acting inconnection with the permanent magnet to divert va part of the lines .offorce and to be automatically retracted. as the magnet became weakened.Instead of this expedient, or even in addition to it, I prefer toisolate the permanent magnet from the shunt-coils and to inclose thelatter in aniron casing, so as to IOC screen the permanent magnet fromthe alter,

nating fields due to the current passing. normally through the meter andfrom the magnetic and inductive effects `due to abnormal disturbances inthe shunt or series coils. To this end, I make use of an iron casinghaving sides l2 l2, a front 13, and a top 14,

lIo5 Y which incloses the coils and actuating-magameter of disk armaturemay -not be necessary, I pivot the same to one side of theoperating-magnet, which, therefore, iiisteadof working in line with adiameter of theI arma#` ture, is disposed in line with a chord'exte'n'ding parallel to the diameter. With this arrangement also 'the speed ofrotation of the disk armature will be diminished, since the impellingforces induced therein act practically on a smaller leveragen With the'con struction described, wherein the coils are-entirely concealed in -a`casing and wherein the permanent magnet is arrangedoutside 'ofl thecasing, it is impossible 'to note the position of the poles withrespect'to the arma#v ture when the two are adjusted relatively by IIOIn this constrnca 15 tion, in order that a prohibitively-'large dirermeans of an adj usting-screw 1S, and it is also impossible to protectthe permanent magnet from outside influences except by the externalcover ot' the meter. I therefore prefer to use the modilication shown inFigs. 5 and 6, wherein the operating-magnet is arranged between two ironwalls 19 and 20, the disk armature projecting through the latter wall,and wherein the. permanent magnet is arranged between the wall 20 and aniron wall 2l, as shown. In' this way I secure two separate cells orboxesone for the electromagnetic motor and the other for the permanentmagnet, the latter being protected both from inliuences within themotorand from outside influences, whilelat the same time it will be possibleto examine the motor or permanent magnet by merely removing the outsidecover of the meter.

With the form of device shown in Figs. 1, 2, 3, and 4 the stationaryarmature 9 is cenlrally pivoted, as I describe in my said patent,whereby the starting torque of the motor can be regulated by changingthe position of said armature, due, probably, to the fact that the linesof force established by the shunt-coils pass them obliquely through therotating armature to reach the pivoted armature 9 and in so doingproduce a distortion of the field acting upon the movable armature.

Vith-the form of device shown in Figs. 5 and 6 the armature 9 is notpivoted, but a supplemental or auxiliary controlling-armature 22 is madeuse of, the latter being pivoted at 23 and being operated by athumbpiece 24, carrying at its lower end a small iron block 25, formingpractically a part of armature 22, workin/g in an opening or slot in thearmature 9, as shown. By shifting the position of the auxiliary armature22 the same Aeffect will be Vsecured as when the armature 9 is pivotallymounted, as explained in said `Instead of making use of a mainoperatingmagnet, as explained, comprising two separate laminatedleg-sections the cores and yoke may be constructed'of separate stampedsheets of the form shown in Fig. 7, each sheet having a cut-away'portion 0,6, forming separate poles around which the series coils arewound.

Having now described my invention, what I claim as new, and desire tosecu re by Letters Patent, is as follows:

l. In an` electric meter of the type described, the combination with anactuatingmagnet, a rotating armature and a permanent retarding or brakemagnet, of a magnetic bridge or diverter extending between the cores ofthe actuating-magnet, substantially as and for the purposes set forth.

2. In an electric meter ot' the type described, the combination with anactuatingmagnet, a rotating armature and a permanent retarding or brakemagnet, of a magnetic bridge or diverter extending between and inclosingthe cores of the actuating-magnet, substantially as and for the purposesset forth. p

3. In an electric meter of the type described, the combination with anactuatingmagnet, a rotating armature and a permanent retarding or brakemagnet, of a magnetic bridge or diverter extending between and'inclosing the cores ofthe actuating-magnet and with free air-spacessurrounding said cores, substantially as and for the purposes set forth.y

4. In a meter of the type described,the combination with theactuating-magnet having divided or split cores, shunt-coils on saidcores, series coils on one or more of the split portions of said cores,and a rotating armature, of a magnetic bridge or diverter extendingbetween said cores, substantially as set forth.

5. In a meter of the type described, the combination with theAactuating-magnet having divided or split cores, shunt-coils on saidcores, series coils on one or more of the split portions of said cores,and a rotating armature, of a magnetic bridge or diverter extendingbetween said cores between the shunt and series coils, substantially asset forth.

6. In a meter of the type described, the combination with theactuating-magnet having divided or vsplit cores, shunt-coils on. saidycores, series coils on one or more'of the split portions o'f said cores,and a rotating armature, of a magnetic bridge or diverter extendingbetween said corjes and inclosing the same, substantially as setforth.

7 In a meter of the type described, the combination with theactuating-magnet, shunt and series coils thereon, and an armature, of amagnetic bridge or diverter extending between and inclosing-said cores,said bridge or' diverter being cut away to reduce its inductivecapacity, substantially as set forth.

S. In a meter of` the type described, the combination with the actuatingmagnet, shunt and series coils thereon, and a disk armature pivotallymounted at one side of said magnet, of a metal shield inclosing themagnet and having a slit through which the disk armature extends, and apermanent magnet coperating with the disk armature outside of saidshield, said shield beingopen-sided to permit inspection ot the armatureand magnet, substantially. as set forth.

9. In a meter of the type described, the combination with the actuatingmagnet,

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shunt and series coils thereon, and a disk armature pivotally mounted atone side of said ma gnet,'ot a metal shield inclosing the magnet-andhaving a slit through which the disk armature extends, a permanentmagnet cooperating with the disk armature outside of said shield, and ametallic shield on the other side of said permanent magnet forprotecting the same from outside'innences, substantially as set forth.l

10.*In a nnetei` of the Atype described, the combination with anactuating-magnet,shunt and series coils thereon, and an armaturecooperating with said magnet, of a stationary armature on the oppositeside of said rotating armature,`and `al. supplemental or auxiliaryarmature adjustable with respect to the 1o stationary armature,substantially as set forth.

This specification signed and witnessed this 28th day of February, 1901.

EMILE BATAULT. Wi messes:

HORACE LEE WASHINGTON, L. H. MUNIER.

